Body weight of humans is determined by the weight of the different parts in the body, like that of bones, muscle, organs, vessels, adipose tissue, et cetera. During lifetime the contributions of each body part to the total body weight changes. After maturation of the human body has stopped, typically muscle mass will gradually and steadily decrease with time. This decrease results in a decrease of lean body mass (LBM, which is the body mass minus the mass of adipose tissue), despite the fact that total body mass (or body weight) may increase, e.g. due to an increase of the mass of adipose tissue and changed masses of other parts of the body. Ferruci et al. reported about the progression of loss of muscle strength during aging (Ferruci et al. (1996) J Gerontol Med Sci, 51AM123-M130). The strength of a muscle is considered to be dependent on its mass. Its mass depends on the number of muscle fibres, which decreases only after 55 years of age to about 50% at the age of about 80 years, their length, which depends on their trophic condition, and the cross-sectional area, which depends on training (Faulkner et al. (2007) Proc Au P S, 38; 69-75). Muscle strength (strength of handgrip or quadriceps) in normal persons appeared to decrease about 0.5% per year after the 30th year. Typically, this rate of decline of muscle strength increases with age. After the 65th year of age, this decrease in muscle strength has reached a magnitude of 1.5% per year for arm muscles and about 3.5% for leg muscle (Skelton et al (1994) Age and Aging, 23, 371-377). Similar age-associated changes in body composition and muscle strength have also been described by Evans, Cyr-Campbell (1997), J American Dietetic Association, 97(6), 632, and by Campion (1998) N Engl J med, 338(15), 1064-66.
It is important to note that, apart from these chronic age-associated decreases in muscle mass and lean body weight, also temporal and mostly reversible changes therein can occur, which in most cases depend on the applied exercise efforts. For example, Muller observed that during long term bed rest, muscle strength decreased at a rate of about 1% per day (Muller (1970) Arch Phys Med Rehabil, 51, 449-462).
These losses in body weight, lean body weight, muscle mass and muscle strength during aging are considered to be normal and physiological, though undesirable. It would be desirable to provide a way to slow down such effect of normal aging, or even reverse the loss.
It should be noted that in part of the human population these losses have occurred at a greater speed or have occurred for a longer period of time to reach a critical level. This abnormally large weight loss is in most cases associated with several health problems which occur at the same time. It is thought that a complex general and non-specific malfunction of the human body causes a low capability of the human body to adapt to the prevalent circumstances to which the individual is exposed. This general condition is recognized by physicians as an independent health problem for which the word sarcopenia was proposed. In the past, different tools have been used to arrive at the diagnosis sarcopenia. Further, abnormal weight loss may result in health problems, in particular frailty (mild or moderate) or prefrailty.
Frailty is a large problem to the individual which experiences it, to the environment and to society. It has a large impact on the individual's life and creates huge costs for medical care. For this reason, the problem is recognized in the prior art as a geriatric syndrome that is distinct from disability and comorbidity. In addition, a relatively low lean body mass and body weight in elderly and especially in persons experiencing neurological problems, is common and a large problem, which has not yet been solved in the prior art.
Food intake, lifestyle and metabolic properties, including energy expenditure, of an individual change with increasing age, which may lead to what has been called a “physiologic anorexia of aging”. Dietary habits, nutrient intake, life style and the aging process are interrelated. For example, with decreasing activity during the applied life style, and the age-associated decline in basal metabolic rate, neuro-endocrine function, immune function and taste and smell perception, older people tend to consume less food, and consequently fewer nutrients, which may lead to a nutritional status, which does not the specific requirements of the elderly of the frail individuals. This complex combination of events which is specific to aging individuals, can result in a further decrease in body weight, lean body mass or body mass index (BMI). This may even result in frailty, as defined above. whereas, the use of specific components to reduce loss in body weight or increase body weight in order to prophylactically or therapeutically treat frailty is generally considered as a medical treatment, the present disclosure is in particular directed at a non-medical use. Involuntary weight loss during aging above 65 years is strongly associated with impaired mood and low stamina.
In a specific embodiment of the invention, the specific combination of components according to the invention was found not only to increase BMI, but also resulted in an improvement of the activities of daily living (ADL). Further it may improve the cognitive function. The composition according to the invention may also have a beneficial effect on exhaustion or fatigue, as will be explained below.
The combination of low stamina, low drive to perform normal activities to keep independence and low abilities of skeletal muscles to allow the activities of daily living may result in a low degree of activity during daily life, including the ability to purchase, prepare or consume adequate food quality and quantity.
Therefore, there is a need to effectively improve the nutritional status in mammals, ion particular humans, more in particular in elderly, having an undersirably low body weight (low BMI in humans), in particular by increasing lean body mass, healthy body weight, muscle capacity. Preferably, these effects are achieved in non-frail or prefrail persons, frail or prefrail elderly or elderly having a BMI below 23.5 kg/m2. More preferably, these improvements in health result in a higher amount of activities during daytime, especially during wake time and in general a better functioning in life and quality of life.
This specific improvement of the nutritional status of a subject is, in particular a non-frail or prefail human having a relatively low body weight, is defined to be the nutritional management of the (nonfrail or prefrail) consumer. In the nutritional management of consumers, and especially elderly it is also important to recognize the problem of xerostomia or a dry mouth in general or during eating, and the problem of hypochlorhydria, i.e. the reduced secretion of hydrochloric acid by the stomach, in general or after food intake or after smelling or seeing the food. In one embodiment of the invention it is an objective to provide a nutritional composition which, when consumed, is well tolerated and even appreciated by persons who suffer from xerostomia or hypochlorhydria.
It is known in the prior art that supplementation of protein and energy to elderly who are at risk from malnutrition produces a small but consistent weight gain (Milne et al. (2009) Cochrane review). Healthy persons like athletes can increase their BMI, when very high amounts of specific proteins, peptides or amino acids are consumed, in particular when this is combined with an exercise protocol. The known approach to supplement additional protein and energy demands consumption of food on top of daily meals, and a proper organ function, for dealing with the large amount of dietetic protein (i.e. nitrogen). in particular, the elderly, may experience difficulties with consuming large quantities or volumes of food, may suffer from impairments in body and organ function or from early satiety and low appetite, have practical problems with cooking and with consuming the food products, and are not keen on or capable of applying exercise programs (Holmes (2008) Nursing standard, 22 (26), 47-57).
Accordingly, there is a need for an alternative way of nutritional management of elderly which are in need of an increased body weight, body mass index, lean body weight, muscle mass or muscle strength, to perform appropriately, especially elderly
Preferably, the composition according the invention achieves all benefits as described above at about the same time. This is observed in elderly in general (above 65 years of age), but also in a subgroup thereof, the oldest one (persons above 75 years of age). In a preferred embodiment, the nutritional composition according to the invention is to be used for treating increasing low body weight or BMI and for improving activities of daily living (ADL), especially in persons older than 50 years of age, more in particular those older than 65 years of age (elderly) and in particular older than 75 years of age (the oldest). The composition according to the invention may also be used to combat other undesirable effectsy, such as exhaustion or fatigue by its effect on muscle power, and thrive or stamina and the effect on neurological performance, in particular cognition.